Image Processing System and Computer Readable Medium

1. An image processing system comprising: an image reception unit that receives an image including an additional entry portion; a first additional entry portion extracting unit that extracts the additional entry portion from the image, which is received by the image reception unit, by using a first threshold; a threshold calculating unit that calculates a second threshold based on a feature in an area alongside the additional entry portion extracted by the first additional entry portion extracting unit; a second additional entry portion extracting unit that extracts the additional entry portion from the image, which is received by the image reception unit, by using the second threshold calculated by the threshold calculating unit; a concealment area specifying unit that specifies an area to be concealed in the image based on the additional entry portion extracted by the second additional entry portion extracting unit; and an image concealment unit that conceals the area specified by the concealment area specifying unit in the image, wherein the threshold calculating unit uses one of pixel density and line segment amount in the area as the feature in the area, wherein the line segment amount used by the threshold calculating unit is the amount of a line segment along a direction of a shorter side in a case where the length of a longitudinal side of the additional entry portion extracted by the first additional entry portion extracting unit is compared with the length of a lateral side thereof.

2. An image processing system comprising: an image reception unit that receives an image including an additional entry portion; a first additional entry portion extracting unit that extracts the additional entry portion from the image, which is received by the image reception unit, by using a first threshold; a threshold calculating unit that calculates a second threshold based on a feature in an area alongside the additional entry portion extracted by the first additional entry portion extracting unit; a second additional entry portion extracting unit that extracts the additional entry portion from the image, which is received by the image reception unit, by using the second threshold calculated by the threshold calculating unit; a concealment area specifying unit that specifies an area to be concealed in the image based on the additional entry portion extracted by the second additional entry portion extracting unit; and an image concealment unit that conceals the area specified by the concealment area specifying unit in the image, wherein the second threshold calculated by the threshold calculating unit is a value capable of extracting a larger area than the additional entry portion extracted by means of the first threshold; and the second additional entry portion extracting unit extracts an additional entry portion, by using the second threshold, from an area alongside the additional entry portion extracted by the first additional entry extracting unit.

3. A non-transitory computer readable medium storing a program causing a computer to execute a process for performing image processing, the process comprising: receiving an image including an additional entry portion; extracting the additional entry portion from the received image by using a first threshold; calculating a second threshold based on a feature in an area alongside the extracted additional entry portion; extracting the additional entry portion from the received image by using the second threshold; specifying an area to be concealed in the image based on the additional entry portion extracted by using the second threshold; and concealing the specified area to be concealed in the image, wherein the calculating the second threshold comprises using one of pixel density and line segment amount in the area as the feature in the area, wherein the line segment amount is the amount of a line segment along a direction of a shorter side in a case where the length of a longitudinal side of the additional entry portion extracted by using the first threshold is compared with the length of a lateral side thereof.

4. A non-transitory computer readable medium storing a program causing a computer to execute a process for performing image processing, the process comprising: receiving an image including an additional entry portion; extracting the additional entry portion from the received image by using a first threshold; calculating a second threshold based on a feature in an area alongside the extracted additional entry portion; extracting the additional entry portion from the received image by using the second threshold; specifying an area to be concealed in the image based on the additional entry portion extracted by using the second threshold; and concealing the specified area to be concealed in the image, wherein the second threshold is a value capable of extracting a larger area than the additional entry portion extracted by means of the first threshold, and extracting the additional entry portion from the received image by using the second threshold comprises extracting an additional entry portion, by using the second threshold, from an area alongside the additional entry portion extracted by using the first threshold.